Perma-Cast® Sierra Stain™ is a penetrating reactive stain that chemically combines with cured concrete to produce permanent variegated coloring effects. Perma-Cast® Sierra Stain™ is perfect for exterior hardscapes artificial rock formations, interior floors, walls, statuaries and countertops. Because there are so many variables involved in the chemical reaction process i.e. the age, porosity, texture, and color of the concrete substrate each application of Perma-Cast® Sierra Stain™ produces unique results.